This application claims the priority benefit of Taiwan application serial no. 91121716, filed on Sep. 23, 2002.
1. Field of Invention
The present invention generally relates to technology for manufacturing a handheld device. More particularly, the invention relates a handheld device, such as a personal digital assistant (PDA), with function of electrostatic discharge (ESD) protection. The handheld device can be tested before assembly of a housing thereof.
2. Description of Related Art
As the great improvement of processor performance and the great development of the Internet and multi-media technologies, the electronic products have been a part of the life with strong relation. Portable computing and communication devices are quickly becoming ubiquitous tools for both business and personal activities. The smallest and lightest of these devices are suitable for and most often carried and operated while being held in the hand of its user. A handheld electronic device, such as the PDA, now has become more and more common in today""s society. The term PDA refers generally to mobile computer systems, typically handheld, which users employ for a variety of tasks such as storing telephone and address lists (databases), calendaring information, task (i.e., to-do) lists, etc. Some PDAs also incorporate a wireless communication link, allowing the unit to operate as a portable facsimile device, Internet access device and/or pager.
Usually, a handheld device includes a circuit part, such as a printed circuit board (PCB) part, and a displaying part, such as a liquid crystal displaying module (LCDM). Both the circuit part and the displaying part are assembled into a handheld housing. Taking a PDA 100 as an example for the handheld device, as shown in FIG.1, the PDA 100 includes an LCDM 130, a PCB 140 and a housing, in which the LCDM 130 and the PCB 140 are assembled inside the housing after assembling.
In order to allow the LCDM 130 and the PCB 140 to be assembled inside the housing, conventionally, the housing is divided into an upper housing 110 and a lower housing 120. The LCDM 130 is affixed to the upper housing 110 via several screws 150. Likewise, the PCB 140 is affixed to the lower housing 120 via several screws 160. In order to allow the screws 150, 160 to hold the LCDM 130 and the PCB 140 and affix them to the housing, it needs additional securing pieces 170 in the upper and lower housings 110, 120 engaging with the screws 150, 160, as shown in FIG. 2. FIG. 2 is a cross-sectional view, schematically illustrating the PDA after being assembled. The housing needs the securing pieces 170 to threadedly engage with the screws 150, 160. After the LCDM 130 and the PCB 140 are respectively affixed to the upper housing 110 and the lower housing 120, the upper housing 110 and the lower housing 120 are assembled together. A data bus connection member (not shown) is used to electrically connect the LCDM 130 and the PCB 140 together to form a data transmission path.
The LCDM 130 and the PCB 140 include many electronic devices, which are usually sensitive to electrostatic discharges (ESD). Thus, an ESD protection is required for the PDA 100. Nevertheless, the structure of the conventional PDA 100 cannot provide a reliable and simple ESD protection.
Furthermore, in this conventional structure, the assembling procedure is tedious. Moreover, after the LCDM 130 and the PCB 140 are assembled to the housings 110, 120 of the PDA 100, usually the PDA is necessary to be tested, such as/mechanical electrical test, before distributing the PDA to the market. The test is to assure that the PDA is firmly assembled together and the electrical connection thereof is proper. In other words, the PDA distributed in the market should satisfy some predetermined requirements.
If the PDA cannot satisfy the predetermined requirements, it needs repair, such as replacing the PCB 140 or the LCDM 130. As foregoing descriptions, the conventional structure of the PDA 100 needs a tedious assembling procedure. Accordingly, the procedure for repairing the PDA 100 is also tedious, which causes the conventional PDA 100 to have a high manufacturing cost.
In addition, the ESD protection of the conventional PDA 100 is achieved by employing an individual element of the PDA. Such an individual element not only increases the tedious assembling procedure, but also may increase the size of the PDA.
One objective of the present invention is to provide a handheld device with the capability of ESD protection, wherein the ESD protection element is an integral part of a subassembly for mounting a circuit member and a displaying member of the handheld device. As a result, the present invention does not need an additional element for achieving the ESD protection.
Another objective of the present invention is to provide a handheld device, in which a PCB member and a displaying module can be firmly affixed together on a supporting frame so that the handheld device can have a robust structure.
Another objective of the present invention is to provide a handheld device, in which a PCB member and a displaying module are first assembled together before they are mounted in a housing of the handheld device. In this manner, a test can be performed when the PCB member and displaying module are exposed. Thus, the PCB member or the displaying module can be easily repaired or replaced if it is found with problem during the test.
To achieve the objectives set forth above, a handheld device in accordance with the present invention comprises a circuit member, a displaying member, and a conductive supporting frame with a hollow region. The circuit member and the displaying member are affixed to the conductive supporting frame at the hollow region. The supporting frame surrounds ESD-sensitive components of the circuit member and the displaying member to thereby provide ESD protection to the ESD-sensitive components of the circuit member and the displaying member.
In the foregoing structure of the handheld device, the circuit member includes a plurality of first holes. The displaying member includes a plurality of second holes. The conductive supporting frame includes a plurality of threaded holes. The circuit member and the displaying member are affixed to the supporting frame respectively on and in the hollow region by extending screws respectively through the first holes as well as the second holes to secure in the threaded holes.
The handheld device further includes a housing to hold therein a subassembly consisting of the circuit member, the displaying member, and the conductive supporting frame. The circuit member includes a printed circuit board (PCB) member and the displaying member includes a liquid crystal displaying module (LCDM). The housing consists of upper and lower housings with a gap therebetween. The conductive supporting frame is located just beside the gap.
The invention also provides an assembling method for a handheld device, which includes a circuit member, a displaying member, an upper housing, and a lower housing. The method comprises providing a conductive supporting frame, which has a hollow region. The displaying member and the circuit member are affixed to the conductive supporting frame at the hollow region, whereby the conductive support frame surrounds the displaying member and ESD-sensitive components of the circuit member to provide ESD protection thereto. The upper housing, the lower housing, and the conductive supporting frame with the displaying member and the circuit member are assembled to form the handheld device, wherein the upper housing and the lower housing form a housing of the handheld device receiving the supporting frame, circuit member and displaying member therein.